1. Field of the Invention
The present invention relates to the verification and validation of bar code labels printed for identification of products. More particularly, a system is provided for scanning bar codes in real time as printed or passed by a scanner in a production environment allowing verification of the quality of the bar code to a plurality of standards, readability of the bar code and proper encoding of desired data. Scanning is accomplished in a synchronized or free-scan format, with the system providing control outputs for use by a printer or process based on the bar code verification or validation results.
2. Prior Art
Bar codes are extensively used for identification of products sold in the commercial market, process procedures and routings, materials and data indexing, cataloguing and storage, and other data administrative and control activities. The development of low cost systems for printing bar codes, including thermal and laser printer systems, has allowed the use of bar codes to proliferate throughout industry. Numerous standards have been developed for bar code encoding schemes and quality, including UPC/EAN/JAN, CODABAR and IATA, with evaluation criteria, including bar width deviation, ratio calculation, percent decode calculation, encodation check, modcheck calculation, quiet zone check and intercharacter gap (ICG), print contrast (PCS), and decodability grade and reference decode calculations by ANSI. The printing of bar code symbols with assured quality and decodability requires on-line verification and/or validation of the bar codes as printed in real time. Similarly, for bar codes applied to products, verification that labels have not been damaged or degraded or that incorrect labels have not been applied to the goods also requires real time on-line evaluation. Various prior art systems have provided differing levels of verification or decoding of bar codes of different symbologies, however, such systems typically do not provide sufficient flexibility in verification or decoding techniques, require significant calibration inputs or lack sufficient communication and control output capability to provide useful service in real time applications.
It is therefore desirable to provide an on-line verification and validation system which has sufficient flexibility to verify bar code symbols to industry specifications and validate data to ensure actual encoded information is accurate without extensive or repeated calibration of the system. Further, it is desirable to provide a system having flexible control and data outputs for accumulation of historical data and response to inaccurate or unreadable bar code information.